It is hypothesized that pituitary tumor induction may be related to disorder hypothalamic secretion leading to unrestricted, polyclonal pituitary cell hyperplasia. Alternatively, these tumors may arise from a somatic mutation in a single cell, producing a monoclonal tumor. Pituitary tumor tissue is are acquired for genetic and histmorphologic studies. Thus far, RAS mutations have been found to be uncommon. Studies of other candidate genes and ongoing tumor acquisition is planned in the coming year.